Control circuit for hydronic system



Feb. 23, 4965 A. B. CHADWICK CONTROL CIRCUIT FDR HYDRONIC SYSTEM Filed Aug. 21, 1965 atop Down 4 3m w mm fIIIIM m al v.6 m D Tr 6 I 2 2 IIIL 4 Relay 32 Burner 44 Transf.

INVENTOR Abraham 8. Chadwick ATTORNEY coN'rnoL CIRCUIT FOR uYnRoNrc SYSTEM Abraham B. Chadwick, Jefiersontown, Ky.,' assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Aug. 21, 1%3, Ser. No. 303,595 12 Claims. (Cl. 236-1) This invention relates generally to zone temperature control systems and more particularly to an improved rality of zone areas, the heating unit is generally of a size sufficient to supply heat to each zone area simultaneously to maintain [all of the zone areas at a given temperature or temperatures during all anticipated weather conditions.

Very frequently, however, and particularly during weather which is not severe, heat is supplied intermittently rather than continuously to the various zones.

Thus, if all the zones require. heat simultaneously the furnace associated with the hot Water boiler will become operative to supply heat to each zone area. Unfortunately, however, the furnace will also become operative when only one zone area calls for heat. Obviously, the demand for heat from less than the total number of zones results in heat requirements which are considerably less than the operating capacity of the boiler output.

It is an object of this invention to provide an improved apparatus for controlling the operation of the heating system in a multi-zone area. a

It is, also an object or this invention to provide an im proved apparatus which will provide increased economy in the operation of a heating system of amulti-zonearea.

It is still another object of this invention to provide an improved apparatus which is reliable in operation and economical to build. 7

Other objects and many oi -the attendant advantages of this invention will be readily appreciated as the apparatus becomes better understood by reference to the fol- United States Patent 2 the water through the heatexchanger. Activation of the second zone thermostat does not result in the imme- 'diate operation ofthe burner of the hot water heating unit. A delay means is provided to delay the operation of the burner for a predetermined interval of time. Therefore, when the contacts of the second thermostat close the heat that is fed to the second zone is that residual heat which is present in the Water. Under ordinary circumstances, the residual heat present in the water is sufficient to increase the temperature of the second zone to that of the thermostat setting before the expiration of the predetermined interval of time for which the delay means is set, and the contacts of the thermostat will open prior to the activation of the burner. If, however, the temperature of the second area is not raised to the setting of the thermostat within the predetermined interval of time for which the delay means is set, then the contacts of the thermostat will not openand the boiler'burner will be activated and remain so until the temperature of the second zone is at least that of the thermostat setting. If an area has more than a first and second zone, then all zones other than the first or master zone are connected to operate in a manner similar to that of the second zone.

Referring now to the figure there is shown a three zone temperature control hot water system incorporating the principles of the invention. A first or master zone 10 incorporates a temperature sensitive means such as a thermostat control 12 or the like and a heat exchanger 14; a secondzone 17 incorporates a temperature sensitive means such as a thermostatic control 16 or the like" and a heat exchanger 18; a third zone 20 incorporates a temperature sensitive means such as a thermostatic control 22 or the like and a heat exchanger 24.

A hot water boiler 26 having a water outlet 28, a water I inlet 30 and a burner unit 32 has a heating capacity which is sufiicient'to provide heat for each of the zones 10, 15 and 2h simultaneously. The water outlet 28 is connected, in shunt, through each of the heat exchangers 14, 18 and 24 to the Water inlet 30. A circulation pump 34 is con-' nected to move the hot water from the boiler 26 through the heat exchangers 14, 18 and 24 and then back to the boiler. Fluid control means such as zone valves operate lowing detailed description when consideredin connection with the accompanying drawing wherein the figure is a schematic of structure in accordance with the. principles ofthe invention.

Briefly, in this invention, 'ama'ster zone andiano ther orsecond zoneare maintained at predetermined temperaelectrically to permit 'or retard the passage of a fluid such as water or the like are provided to permit, or prevent the flow of water through the heat exchangers. Zone valve 36 is positioned to permit or retard the flow of water through heat exchanger 14; zone valve 38 is positioned to permit or retard the flow of water through heat exchanger retard minals 44 and 4&5 of 'a step-down transformer 48, to the tures by meansof a hot .water heating installation operating under the control of a thermostatic switch, ,Immediatelyupon the closing of the contacts of the thermostat associated with the master zone the burner of a'hot water heating unit, the zone yalvea'nd' the circulation pump become operative. Upon the closing of the contacts-10f the second zone thermostat, thersecond zone valvebecomes operative immediately, howeventheoperation'of the burnenof'the hot water heating unit'isf delayed for a means. fllherefore,- activationj'of the first or master zone thermostat-resultsin immediate operation of, the burner to heat'the water in the boiler which is circulated by the circulation pump through the zone valve and, the heat exchanger, in the first zone. Activation of the second zone thermostat results in'the immediate operation of the predetermined interval of. time as determined by adelay which will not retard the how ofwater.

With'the water circulation pump" 34 and input terminals of .a relay" unit 42 and-to the input terminals of a relay unit The transformer 48 supports two output terminals 56}, 52, terminal 50 being connected to'a ground terminal and terminal 52 being connected to. a contact of each of the thermostat control units 12, 16and 22. w 'The contact 13 of thermostat 12 is coupledto feed signal to .thezone valve 36, the relay unit" 43 associated i the relay unit 42 associated with the burner unit 32. g a I .The' feeding of a signal from any 'of the thermostats to'relay unit 42 activates the burner32 and the feeding of a signal from any of the thermostats to relay unit 43'' Q activates circulation pump 34. :A signal fed to a zone valve 36,68, 40 urges the valve to assumea position Naturally, termination of the signal from the thermostat results in the stopping of the operation of the burner 32 and circulation pump 34, and the zone valve or valves activated assume; a position'which will retard the flow of Water.

; v 3 f The contact 15 of, the thermostat 16 is coupled to feed a signal'to the zone valve 38, to the relay unit 43 of the water circulation pump '34 and to relay :umt dl of the:

burner 32 through a delay means 54,

The contact 21 of the thermostat 22 is coupled to feed 'a signal to the zone valve itl, to the relay unit d3 of the water circulation pump 34 andto the relay unit 42 of the burner through a delay means 56.

'In some instances it, may be desirable to incorporate I the two delay means 54, into a singledelay means 57.

'In operation, a source of potential is coupled tothe terminals'SS, 60 to feed a signalto the relay, unit 42, to

water to flow through the heat exchanger 14. The relay unit 43' is energized and operates'the circulation pump 34 which pumps hot water from the boiler 26, through The relayunit 42 is energized and operates burner 32 whiclrheats'the water in the boiler 26. The burner 32 can be either of the, oil or gas type, Thus, immediately upon the closing of the contacts of the thermostat-l2 theburner 32fis activated and. heats the water in' the boiler 26 which is pumped. through to the heat exchanger If,;however-, it is assumed that the temperature in zon'e'17dropssuficiently'to cause the contacts of ther mostat 16 to close,.then a signal is fed throughthermostat 1'6,to zone valve 38, to the relay unit 43-:whichis' then energized and operates the water circulationpump 34 and the delay means 54. :The zone 'valve 33 operates 34 is activated'and pumpshot water from the, boiler 26 throughthe heat exchanger 18 and then'backflto the interval of time, feeds asig nal through to the relay uni't the thermostat lo first close, theheattransferred to the heat exchanger is that residual heat which is present in r the water. "The burner isnot operative and noadditional heat is supplied to the water. If, after a predetermined interval of time as determined by the setting of the delay means the residual heat present the water has not been sufficient to -raise the temperatureof the zone above that for which the-therrnostat is set, then a s'ignal'is. passed .by the delay means'to therelay unit 42am the burner 32 is. activated; In practice it has been found that this invention operates in a verysatisfiactory manner if :the ,delay means is preset to provide 'a' delay interval of time 7 I from 10 to 20 minutes. Thus, upon the closing of the I contacts of the thermostat 16, hot water 'is circulated. I through heat exchanger 18, but the'burner isnot activated; 1 This]condition/continues for that interval'of time for which the delay means is set. ll? the temperature in v the zone is increased to the setting of' the thermostat prior-". V to the'termination of the time, for which the delay means i is; set, thenthe contacts of the thermostat will open and prevent operation of the burner. However, ifat the end of that period of time forwhich the delay means is set 'theheat exchanger 14 and then back to the boiler 26. 1

'7 'to' permitthe passage of water and the circulation pump boiler 26. The'signal fed through the thermostat 16 also activates the delay means 54 which, after a predetermined 42 to energizethe burner 32. Thus; when the contacts of operation of the burner.

'of and associated with zone 17.

Thus, it is possible to supply heat to an area without "requiring the activation of the burner. In those instances 'where the thermostat is not satisfied within the'time interval for. which the delay means is set, then the burner begins to operate and supplies the additionabheat required to satisfy the thermostat, and the occupants of the zone dof'not experience anydiscomfort and, in all instances also are not even aware of the delay in the The operation of the structure ofrand tha't associated with zone 20 operates in the same manner'as the'structure Thus, restating, when the thermostat ,Off ZOHe It) indicates'a need for more heat'-the burner becomes operative immediately. However, when the thermostat of zones 17 or 29 indicate a need for more heat-the burner remains inoperative for a time duration equal to. the time delay of the delay means if the residual heat present in the water being recirculated is not sufficient to raise the temperature of the, zone to that for which thethermostat is set. "Naturally, if the zone reaches the temperature for Which the thermostat is set prior to the passing" ofa signal through the delay means to activate the .burnerthe thermostat contacts will open and the burner will not be activated. Continuing,,a demand for more heatby zone 10 will cause the burner to become activated regardless of the operatingconditionof zones 17' and/or'20; 'and a demand byrzone'2il 'for more heat'afterf'zone 17 has indicated a need for more heat means that zone 17 will controlthe time of activation of the burner 32,

Obviously many modifications and variations oi the present invention are possible invthe light of the above teachings.v It is therefore,;to beiundersto'o'd that within 7 the scope of the appendedclaims the-. invent ion may be practiced otherwisethan as specifically'described,

'What is claimed is: V V i a 1. Alone temperature control sy'stem comprising a V first zone; .a first heat exchanger in-said first zonepa secend zone; a second he'at"exchanger-in said second zone;

.a fluid moving means; means coupled to said fiuid mov ing means toteed a fluid-along a first path to said; first heatexchanger and alonga second pathto; said second heat exchanger; first fluidcontrol means to'fcontrol" the; flow of-thefiuidthrough said first heat-exchanger; second fluid control meansto control the flow of the fluid through said second heat exchanger; heating means to heat'said. V

' fluid; a'first temperature sensitive meanstor detecting thetemperaturerin said first zone coupled to saidifirst fluid control jmeans, said fluid moving means andsaid he ating means; a second temperature, sensitive; means for detect- I ing the temperature in said second zone' coupled to said the; thermostat contacts are]stilliclosed, then the burner 7 becomes operative and supplies'heat to the water.-

' 'In'practice-When using structure in accordance' .with 1 the principles of.this' invention it has "generallybeen found that the residual heat in" the water i is "suflicient to raise the temperature of: the' rzone an amount which becomes operative.

second fluid control means,,said;fiuid moving means and .said heating means; and delayjmeans interposed between a .said second temperature sensitive means and said heating means to delaytheoperationiof said heating means for a. I preselected intervalof time; I I I F 2; A zone temperature c'ontrol'system; comprising a first zone; a first heatexchanger in said first zone; a second 1 zone; a second heat. exchanger in said second-zoneya water circulationpump; means coupled to said 'water cir-f 1 1 culation pump to'feedwater; along afir'st pathto' saidfirst heat exchanger and alon a second 'path to said v second heat exchangenfi'rst fluid, control ;means to 'control the flciw-o'ftheiywater, through said first heat; exchanger; secondfiuid cont'rol' means to controlithe flowof the water 'throughss'aid,heatiexchanger; heating means toi heat sa water; 'a' first temperaturesensitive means for detecting the .temperature ,in saidffirstlzonecoupledjto sjaidfirst I :fluidpontr'ol means, said-water circulation pump andsaid heating 'm'eansyasecond temperature sensitive means for detecting the temperature: in said;v second ozone fcoupled toaoperateflsaid seeondffiuid icont ro irnean s', saidwater acirculation 'pnmp and: said -heating-'rheans;,.land idelay J means interposed between- 'saidgs'econditenrp, atute sensitlve means and said heating means jtol-del eorems;

of said heating means for a preselected interval of time.

second zone; a' second heat exchanger in said second zone; a water circulation pump; means'coupled to said water circulation pump to feed water along a first path to said first heat exchanger and along a second path to said second heat exchanger; a. first valve to control the flow of water through said first heat exchanger; a second valve to control the flow of water through said second heat exchanger; a burner to heat said water; a first thermostat for detecting the temperature in said first zone coupled to said first valve, said water circulation pump and said burner; a second thermostat for detecting the temperature in said second zone coupled to said second valve, said water circulation pump and said heating means; and delay means interposed between said second thermostat and said burner to delay the operation of said burner for a preselected interval of time.

4. A zone temperature control system comprising a first zone; a first heat exchanger in said first zone; a second zone; a second heat exchanger in said second zone;a boiler containing water; a water circulation pump coupled to said boiler; means coupled to said water circulation pump to feed water along a first path to said first heat exchanger and along a second path to said second heat exchanger; a first remotely controlled valve to control the flow of water through said first heat exchanger; a second remotely controlled valve to control the flow of water through said second heat exchanger; a burner to heat said water in said boiler; a first thermostat for detecting the temperature in saidfirst zone coupled to said first remotely controlled valve, said water circulation pump and said burner; a second thermostat for detecting the temperature in said second zone coupled to said *second remotely controlled valve, said water circulation pump and said heating means;and delay means interposed between said second thermostat and said burner to delay first fluid controlimeansto control the flow of the fluid through said first heat exchanger; second fluid control.

means to control the flow of the fluid through said 'second heat exchanger; heating means to heat said fluid;

a first temperature sensitive means for detecting the temperatures in said first zone coupled to operate said first fluid control means, said fluid moving means and said heating means; a second temperature sensitive .means for detecting the temperature in said second zone coupled to said second fluid control means; said fluid moving means and said heating means; and delay means preconditioned to pass a signal from 10, to 20 minutes after activation interposed between said second temperature sensitive means and said heating means todelay the operation of said heating means.-

6. A zone temperature control system comprising a first zone; a first heat exchanger in said first zone; a

second zone; a "second heat exchanger in said second zone; a water circulation pump; means" coupled to said water circulation ampas feed Water along afirst path to said first heat exchanger and along a second path .to

said second heat exchanger; a first fluid control means to control the flow of water through said-first heat exchanger; second fluid control valve means to control the sitive meansfor detecting the temperature in said first zone coupled to said first'fluid' control means, said'water circulation pump andsaid heating means; asecond tem-] perature sensitive means for detecting the temperature; 'in said second zone coupled to operate said second fluid control means, said'water circulation pump and said heating meansyand delay means preconditioned to pass a signal from 10 to 20 minutes after activation interposed between said second temperature sensitive means and said heating means to delay the operation of said heating means.

7. A 'zone temperature control system comprising first 'zone; a first heat exchanger in said first zone; a.

said water; a first thermostat for detecting the tempera' ture in said first zone coupled to said first valve, said 1 watercirculation pump and said burner; a second thermostat -for detecting the temperature in said second zone coupled to said second valve, said water circulation pump and said heating meansgand delay means preconditioned to pass a signal from 10 to 20 minutes after activation interposed between said second thermostat and said burner to delay the operation of said burner. Y

8. A zone temperature control system comprising a first zone; a first heat exchangerin said first zone; a

second zone; a second heat exchanger in said .second' zone; a boiler containing water; a water circulation pump coupled to said boiler; means coupled to said water circulation pump to feed Water along a first path to said first heat 'exchangerand along a second path to said sec fiowof the water through said second heat exchanger;

,heating means to heat said water;-a firstjtemper'ature senond heat exchanger; a first remotely controlled valve to control the flow of water through said first heat ex changer; a second remotely controlled valve to' co ntrol the How of water throughsaid second heat exchanger;

a burner coupled to heat said Water in said boiler; a

first thermostat for detecting the temperature in said first zone coupled to said first remotely controlled valve, said water circulation pump and said burner; a second J thermostat'for detecting the temperature in said, second Zone coupled to said second remotely controlled valve,

andsaid second remotely controlled valve and wateric rculation pump. v q

9.]A zone temperature control system comprising a first zone; a first heat exchanger in said first zone; a second zone; a second heat exchanger in said second zone;

a third zone; a third heat exchanger in said third zone;

a fluid movingmeans; means coupled to said fluid moving means to feed a fluid along a first path to said first heat exchanger, along "a second path to said second heat exchanger and along a third'path to said third heat exchanger; first fluid control means to controlthe flow of a the fluid through said first heat exchanger; second fluid control means to control the flow of the fluid throughsaid second heat exchanger; third fluid control means to control the flow of the fluid through said third heat exchanger; heating means to heat said fluid; a first temperature sensitive means for detecting the temperature in said first zone'coupled to said first'fluid control means, said fluid moving means and said heating means; a second temperature sensitive means for detecting the temperature in said second zone coupled to said second fluid control means, said fluid moving means and said heating means; a third temperature sensitive imeanszfor detecting the. temperatures in said third zonecoupled to saidthird fluid control means, and fluid moving means meansfor a preselected interval oftime afterroperation of said second thermosta'tand said second remotely conand saidheating means;p -fi'rst vdelay means interposedbev tween said second temperature sensitivemeans and said. heating means tov delay-the operation of said heating trolled. valve andwater circulationpump; and second delay means interposed between said third temperature sensitive means and said heating means to delay the operation of said heating means fora preselected interval of time after operation of said third thermostatand said a 10. A zone temperature control system comprising a first zone;a first heatrexchanger in said first zone; a secondzone; a'second heat exchanger in said secondizone; a third zone; a third heat exchanger in said thirdzone; a fluidmoving means; means coupled to said fluid moving means to 'feed a fluid along afirst path to said first heat 7 third remotely controlled valve and water. circulation;

pump.

meansto feed a fluid along a firstpath to said first heat exchanger, along'a second path to" said second heat ex changer and along a third path to s'aidthird heatexchanger; first fluid control meansto control theflow. of a the fluid through saidVfirst'heatexchanger;second fluid 1 control means to control the flow oftthefluid through said second heat-exchanger; third fluid'control means to control the flow-of the fluid through said third heat exchanger; heating means to-heat said fluid; a first temperature sensis tive means for detecting thetemperaturein said first zone coupled to said firstfiuid control means, said fluid mov ing meanspand said heating means; a secondtemperature sensitive means for detecting the temperature in said second zone coupled to said second fluid control means, said fluid moving means and said heating means; a third temperature sensitive means for detecting the temperature in said third zone coupled to said third fluid control means,

exchrmger, along a second path to saidsecond heat exchanger. and along a third path to said third heat :ex:

changer;':first fluid controlmeans to control the flow of the fluid through said first heat exchanger; a second fluid control means to control the flow of the fiuidthrough said second heat exchanger; third fluid control means .to control the fiow of the fluid throughsaid third heat exchanger heating means to heat'saicl fluid; a first temperaturesensitive means for detecting the temperature in said first zone V coupled to said first fluid control 1neans,fsaid fluid moving means and said heating means; a'second temperature sen:

sitive means fordetecting the-temperature in said second a zone coupled to said second fluid control means,'said fluid moving means and said heatingmeans; a third tempera? ture sensitive means for detecting the teniperature in said third zone coupled to said third fluid control means, said fl'pid moving means and said heating meansffirst delay means preconditioned torpass arsignal fromzlO to 20 t'minutes after: activation interposed vbetween said second temperature sensitive means andsaid, heating means to V "of said second thermostat and said second remotely con- .trolled, valve, and .Water circulation pump; and second delay means p reconditioned to.,pass-a signal from lOto 20 minutes: afteractivation f interposed between said third delay the operation of, said heating means afteroperati'on interval of time saidlfluid moving mean s and said heating means; delay means fed by said second temperature sensitive means and said third temperature sensitive'means coupled to delay the operation of saidheating means for a preselected l2. Azone' temperaturen'control system comprising a first zone; a first heat exchanger. insaidfirst zone; a second zone; a secondheat exchanger in saidsecond zone; a third zone; a third heat exchanger in. said third zone; a fluid moving means; a means coupled to said fluid moving means toteeda fluid along a first path to said first heat exchanger, along a second path to said second heat exchanger and along a third path to said third heat exchanger; firstrfluid control means to controlthe flow of V t the fiuid throu'gh said first heat exchanger; second fluid control means to controlthe flow of the fluid through said second heat exchanger; thirdfiuid control means to control the flow of the fluid through said third heat exchanger; 1 heating means to heat said fluid; a first temperature sens tive means for detecting the temperature in said first zone I coupled to said firstfluid control means, said fluid moving means and said heating means; a secondtemperature sensitive means for detecting the ternperaturein said second zonecoupled togsaid second fluid controlmeans, said fluid moving means and saidheating means; a third temperature sensitive means for detectingthe temperatemperature sensitive means and said heating meanszto:

delay the operation of said. heating means after operation of said third thermostat and said third remotelycontrol- V led-valve and water circulation pump;

ond zone; a second heat exchanger in, said second Zone;

a' third zone;;-a third heat exchanger insaid third zone; a fluid moving means; means coupled to' said fluid moving 7 11. A zone temperature controlsystem comprisingar first zone; a first heat exchanger in said first zone; a secture in said: third zone coupled 'to said third fluid, control means, said fluid-Ymoving means and said heating means; delay means preconditioned to pass a signalfroml 10. to 20 minutes :after activation fed'by said second temperature sensitive meansand said third temperature sensitivemeans to delay the operation of said heating means. se water-[a in he near this; aar

V g V UNITED isr'A'ras PATENTS" 1 2,096,626 Crago f Oct. 19, 1937 2,153,382 Martina-Quay f Ajprr4, 1939 

1. A ZONE TEMPERATURE CONTROL SYSTEM COMPRISING A FIRST ZONE; A FIRST HEAT EXCHANGER IN SAID FIRST ZONE; A SECOND ZONE; A SECOND HEAT EXCHANGER IN SAID SECOND ZONE; A FLUID MOVING MEANS; MEANS COUPLED TO SAID FLUID MOVING MEANS TO FEED TO FLUID ALONG A FIRST PATH TO SAID FIRST HEAT EXCHANGER AND ALONG A SECOND PATH TO SAID SECOND HEAT EXCHANGER; FIRST FLUID CONTROL MEANS TO CONTROL THE FLOW OF THE FLUID THROUGH SAID FIRST HEAT EXCHANGER; SECOND FLUID CONTROL MEANS TO CONTROL THE FLOW OF THE FLUID THROUGH SAID SECOND HEAT EXCHANGER; HEATING MEANS TO HEAT SAID FLUID; A FIRST TEMPERATURE SENSITIVE MEANS FOR DETECTING 